7-6
DSP56309UM/D MOTOROLA
Enhanced Synchronous Serial Interface (ESSI)
ESSI Data and Control Signals
modes; see
on page 7-8. SCK can be programmed as a GPIO signal (P3) when
the ESSI SCK function is not being used.
Notes:
1.
Although an external serial clock can be independent of and asynchronous
to the DSP system clock, the external ESSI clock frequency must not exceed
F
core
/3, and each ESSI phase must exceed the minimum of 1.5 CLKOUT
cycles.
2.
The internally sourced ESSI clock frequency must not exceed F
core
/4.
7.3.4
Serial Control Signal (SC0)
SC00 is a serial control signal for ESSI0, and SC10 is a serial control signal for ESSI1. They
are referred to collectively as SC0.
The function of this signal is determined by selecting either synchronous or
asynchronous mode; see
on page 7-24. In asynchronous mode, this signal is
used for the receive clock I/O. In synchronous mode, this signal is used as the
transmitter data out signal for transmit shift register 1 or for serial flag I/O. A typical
application of serial flag I/O would be multiple device selection for addressing in codec
systems.
If SC0 is configured as a serial flag signal, its direction is determined by the serial control
direction 0 (SCD0) bit in the ESSI control register B (CRB). When configured as an
output, its value is determined by the value of the serial output flag 0 (OF0) bit in the
CRB. When configured as an input, SC0 controls the state of serial input flag 0 (IF0) bit in
the ESSI status register (SSISR).
When SC0 is configured as a transmit data signal, it is always an output signal
regardless of the SCD0 bit value. SC0 is fully synchronized with the other transmit data
signals (STD and SC1).
In asynchronous mode, SC0 is configured as the receive clock. The direction of the SC0
in this mode is also determined by SCD0.
SC0 can be programmed as a GPIO signal (P0) when the ESSI SC0 function is not being
used.
Note:
The ESSI can operate with more than one active transmitter only in
synchronous mode.
Summary of Contents for DSP56309
Page 25: ...xxii DSP56309UM D MOTOROLA Figure D 25 Port E Registers PCRE PRRE PDRE D 39 ...
Page 30: ...MOTOROLA DSP56309UM D 1 1 SECTION 1 DSP56309 OVERVIEW ...
Page 47: ...1 18 DSP56309UM D MOTOROLA DSP56309 Overview DSP56309 Architecture Overview ...
Page 48: ...MOTOROLA DSP56309UM D 2 1 SECTION 2 SIGNAL CONNECTION DESCRIPTIONS ...
Page 85: ...2 38 DSP56309UM D MOTOROLA Signal Connection Descriptions OnCE JTAG Interface ...
Page 86: ...MOTOROLA DSP56309UM D 3 1 SECTION 3 MEMORY CONFIGURATION ...
Page 104: ...MOTOROLA DSP56309UM D 4 1 SECTION 4 CORE CONFIGURATION ...
Page 124: ...MOTOROLA DSP56309UM D 5 1 SECTION 5 GENERAL PURPOSE I O ...
Page 125: ...5 2 DSP56309UM D MOTOROLA General Purpose I O 5 1 INTRODUCTION 5 3 5 2 PROGRAMMING MODEL 5 3 ...
Page 128: ...MOTOROLA DSP56309UM D 6 1 SECTION 6 HOST INTERFACE HI08 ...
Page 166: ...MOTOROLA DSP56309UM D 7 1 SECTION 7 ENHANCED SYNCHRONOUS SERIAL INTERFACE ESSI ...
Page 212: ...MOTOROLA DSP56309UM D 8 1 SECTION 8 SERIAL COMMUNICATION INTERFACE SCI ...
Page 241: ...8 30 DSP56309UM D MOTOROLA Serial Communication Interface SCI GPIO Signals and Registers ...
Page 242: ...MOTOROLA DSP56309UM D 9 1 SECTION 9 TRIPLE TIMER MODULE ...
Page 269: ...9 28 DSP56309UM D MOTOROLA Triple Timer Module Timer Operational Modes ...
Page 270: ...MOTOROLA DSP56309UM D 10 1 SECTION 10 ON CHIP EMULATION MODULE ...
Page 302: ...MOTOROLA DSP56309UM D 11 1 SECTION 11 JTAG PORT ...
Page 369: ...C 22 DSP56309UM D MOTOROLA DSP56309 BSDL Listing ...
Page 370: ...MOTOROLA DSP56309UM D D 1 APPENDIX D PROGRAMMING REFERENCE ...
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